# MnBr2 on the Graphene on Ir(110) Substrate: Growth, Structure, and Super‐Moiré

## TL;DR

Researchers grew a single layer of MnBr2 on graphene supported by an Ir(110) substrate and discovered a unique super-moiré pattern formed by non-contacting layers.

## Contribution

The study reveals a super-moiré pattern formed by a virtual interaction between non-contacting lattices, enabled by molecular beam epitaxy.

## Key findings

- MnBr2 on graphene/Ir(110) forms a super-moiré pattern due to a virtual moiré between non-contacting layers.
- Growth morphology of MnBr2 changes with temperature, reflecting surface diffusion processes.
- Ab initio calculations and Fourier analysis explain the origin of the virtual moiré.

## Abstract

Single‐layer MnBr2 is grown on graphene (Gr) supported by Ir(110) and investigated using low‐energy electron diffraction, scanning tunneling microscopy, and spectroscopy. The structure and epitaxial relationship with the substrate are systematically characterized. The growth morphology strongly depends on the growth temperature, evolving from fractal to dendritic and eventually to compact dendritic–skeletal islands, reflecting changes in the underlying surface diffusion processes. The pronounced variation in the apparent height with tunneling conditions for the magnetic insulator is explained based on the measured electronic density of states. MnBr2 on Gr/Ir(110) constitutes a three‐lattice system, giving rise to a super‐moiré pattern – a moiré of moirés. The super‐moiré of MnBr2/Gr/Ir(110) is unique, as it involves a virtual moiré of MnBr2 with the Ir(110) surface lattice – two lattices not in contact with each other. Using a careful Fourier analysis, the known properties of Gr/Ir(110), and the results of ab initio calculations, the origin of the virtual moiré is uncovered and related to the inhomogeneous binding of Gr to Ir(110). Comparative experiments with MnBr2 on Gr/Ir(111) show similar growth and structure, but highlight the unique properties of the MnBr2/Gr/Ir(110) super‐moiré.

The study realizes single‐layer MnBr2 via molecular beam epitaxy on graphene on Ir(110), unveiling a unique super‐moiré (“moiré of moirés”) formed by lattices of different symmetries. Remarkably, this super‐moiré is driven by a virtual interaction between non‐contacting layers. Together, these findings demonstrate that molecular beam epitaxy enables the creation of complex quantum architectures that cannot be achieved through conventional stacking of exfoliated layers.